As reported in JAMA, the U.S. Preventive Services Task Force ­(USPSTF) has issued new recommendations for colorectal cancer screening.¹ In brief, the USPSTF recommends colorectal cancer screening starting at age 50 years and continuing until age 75 years (grade A recommendation = “The USPSTF recommends the service. There is high certainty that the net benefit is substantial.”). It recommends that the decision to screen for colorectal cancer in persons aged 76 to 85 years be an individual one, taking into account the patient’s overall health and screening history (grade C = “The USPSTF recommends selectively offering or providing this service to individual patients based on professional judgment and patient preferences. There is at least moderate certainty that the net benefit is small.”).

The USPSTF concludes with high certainty that screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years is of substantial net benefit.

— Kirsten Bibbins-Domingo, MD, PhD, and colleagues

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In updating its 2008 recommendations, the task force reviewed evidence on the effectiveness of screening with colonoscopy, flexible sigmoidoscopy, computed tomography (CT) colonography, the guaiac-based fecal occult blood test, the fecal immunochemical test, the multitargeted stool DNA test (fecal immunochemical test-DNA), and the methylated SEPT9 DNA test.

Kirsten Bibbins-Domingo, MD, PhD, of the USPSTF and the University of California, San Francisco, is the corresponding author of the JAMA article.

Clinical Recommendations

Specific recommendations follow:

• Risk Assessment: For the vast majority of adults, the most important risk factor for colorectal cancer is older age. Other associated risk factors include family history of colorectal cancer, male sex, and black race.
• Screening Tests: There are numerous screening tests to detect early-stage colorectal cancer, including stool-based tests (guaiac-based fecal occult blood test, fecal immunochemical test, and fecal immunochemical test-DNA); direct visualization tests (flexible sigmoidoscopy, alone or combined with fecal immunochemical test, colonoscopy, and CT colonography); and serology tests (SEPT9 DNA test). The USPSTF found no head-to-head studies demonstrating that any of these screening strategies is more effective than another, although they have varying levels of evidence supporting their effectiveness as well as different strengths and limitations.
• Starting/Stopping Ages: The ­USPSTF concluded that the evidence best supports a starting age of 50 years for the general population. The age at which the balance of benefits and harms of colorectal cancer screening becomes less favorable varies based on life expectancy, health status, comorbid conditions, and prior screening status. The USPSTF does not recommend routine screening for colorectal cancer in adults aged ≥ 86 years.
• Treatment/Interventions: Treatment of early-stage colorectal cancer generally consists of local excision or simple polypectomy for tumors limited to the colonic mucosa or surgical resection with anastomosis for larger, localized lesions.
• Balance of Harms and Benefits: For persons aged 50 to 75 years, the USPSTF concludes with high certainty that the net benefit of screening for colorectal cancer is substantial. For those aged 76 to 85 years, the USPSTF concludes with moderate certainty that the net benefit of screening in those who have been previously screened is small. Those who have never been screened are more likely to benefit. Screening is most appropriate for those healthy enough to undergo treatment and those without comorbid conditions that significantly limit their life expectancy.

Modeling of Benefit and Risk

Modeling of benefits and risks associated with stool-based and direct visualization screening methods produced the following middle (vs low or high) estimates per 1,000 persons screened; the serologic SEPT9 DNA test was not included in modeling due to a limited amount of available data. For colorectal cancer deaths averted: 24 for colonoscopy every 10 years; 23 for fecal immunochemical test DNA every year and for flexible sigmoidoscopy every 10 years plus fecal immunochemical test every year; 22 for fecal immunochemical test every year, high-sensitivity guaiac-based fecal occult blood test every year, and CT colonography every 5 years; and 20 for flexible sigmoidoscopy every 5 years and for fecal immunochemical test-DNA every 3 years.

Middle estimates for harms per 1,000 screened defined as gastrointestinal or cardiovascular complications were: 15 for colonoscopy every 10 years; 12 for fecal immunochemical test-DNA every year; 11 for flexible sigmoidoscopy every 10 years plus fecal immunochemical test every year and for high-sensitivity guaiac-based fecal occult blood test every year; 10 for flexible sigmoidoscopy every 5 years, fecal immunochemical test every year, and CT colonography every 5 years; and 9 for fecal immunochemical test-DNA every 3 years.

Middle estimates for burden of screening (ie, lifetime number of colonoscopies per 1,000 persons screened) were: 4,049 for colonoscopy every 10 years, 2,662 for fecal immunochemical test-DNA every year, 2,289 for flexible sigmoidoscopy every 10 years plus fecal immunochemical test every year, 2,253 for high-sensitivity guaiac-based fecal occult blood test every year, 1,820 for flexible sigmoidoscopy every 5 years, 1,757 for fecal immunochemical test every year, 1,743 for CT colonography every 5 years; and 1,714 for fecal immunochemical test-DNA every 3 years.

As stated by the authors:

The USPSTF concludes with high certainty that screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years is of substantial net benefit. Multiple screening strategies are available to choose from, with different levels of evidence to support their effectiveness, as well as unique advantages and limitations, although there are no empirical data to demonstrate that any of the reviewed strategies provide a greater net benefit. Screening for colorectal cancer is a substantially underused preventive health strategy in the United States. ■

Disclosure: For full disclosures of the study authors, visit www.jama.jamanetwork.com.

Reference

1. U.S. Preventive Services Task Force, et al: JAMA 315:2564-2575, 2016.